fix(search): bound retrieval and avoid repeated turn admission (#7888)

* fix(search): bound retrieval and billing query cost

* refactor(billing): remove unneeded synchronous cost projection

* fix(billing): authorize continuations without repeating spend admission

* fix(test): align session policy fixture with joined billing read

Author: icecrasher321

.github/workflows/test-build.yml

@@ -17,6 +17,15 @@ jobs:
       matrix:
         provision: [push, migrate]
     services:
+      redis:
+        image: redis:8.2-alpine
+        ports:
+          - 6379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 5s
+          --health-timeout 5s
+          --health-retries 10
       postgres:
         image: pgvector/pgvector:pg17
         env:
@@ -109,7 +118,8 @@ jobs:
         working-directory: apps/sim
         env:
           BILLING_USAGE_TEST_DATABASE_URL: postgresql://postgres:postgres@127.0.0.1:5432/sim_auth_scim
-        run: bunx vitest run lib/billing/core/usage-log.postgres.test.ts lib/billing/core/organization-activity.postgres.test.ts
+          BILLING_USAGE_TEST_REDIS_URL: redis://127.0.0.1:6379
+        run: bunx vitest run lib/billing/core/usage-log.postgres.test.ts lib/billing/core/organization-activity.postgres.test.ts lib/billing/calculations/usage-reservation.test.ts
 
       - name: Verify cumulative billing timeout recovery on PostgreSQL 16
         if: matrix.provision == 'push'